When central venous pressure (CVP) monitoring fell out of favor, so did the routine placement of central lines for cases involving significant blood loss or major physiological shifts. Still, central access remains a smart and sometimes necessary choice in cases with a high amount of blood loss or expected use of critical vasoactive agents.

The shift to ultrasound-guided placement over the traditional landmark approach has been a major step forward in terms of safety. However, while ultrasound guidance has reduced complications, it hasn’t made the procedure “easy” by any means. It still requires judgment, dexterity, and a solid understanding of the anatomy. Like videolaryngoscopy, ultrasound may improve visualization, but it should never give you a false sense of security.

Before placing any central line, take a step back and assess the broader context. Are there surgical contraindications to your intended site—for example, a planned neck dissection over the internal jugular? Does the patient have a known vascular anomaly, such as subclavian stenosis? Is there any other hardware in the vessel that you need to be mindful of? Medi-port, PICC line, dialysis catheter, etc.?

Once you have selected an ideal insertion site, here are some tips to ensure safe and effective central line placement:

• If time permits, begin by pre-scanning the site with ultrasound before prepping. This lets you assess the vessel’s patency, compressibility, and depth, and helps you choose the best cannulation point.
  
• Once you center the target vessel on the screen, keep things as steady as possible in your ultrasound hand. Your hand + probe should stay still, and the only moving object should be your needle. You can use your thumb to anchor the probe, so it does not wander from side to side.
  
• For internal jugular (IJ) cannulation, I advise trainees to err on the side of inserting the needle more medially on the screen and advancing slightly laterally. This reduces the risk of carotid puncture, which often results from a natural tendency to angle the needle too medially.
  
• Instead of aligning the ultrasound probe with the patient’s neck angle, which would direct the needle medially, orient it parallel to the floor.
  
• Throughout the procedure, remember: this is a hybrid screen-and-patient procedure. Don’t fixate on the ultrasound screen. Your gaze should continually alternate between the screen and the patient. If you only watch the screen, you might miss visual cues, such as that your needle is oriented in an odd way or the needle has inserted so far that you are already at the hub. The longer your eyes are off the field, the more likely you are to cause unintended trauma. Keep scanning both environments.
  
• Your attempts should be deliberate and precise. If you don’t see a flash of blood, don’t just keep jabbing the needle in multiple directions. That approach defeats the entire purpose of ultrasound guidance and risks injury to nearby structures. Instead, calmly withdraw the needle to skin level and reattempt with a better view of the vessel.
  
• When you do get flash, stop. Confirm you’re in vein by gently aspirating, looking for a steady return of venous blood. Resist the very common urge to keep advancing the needle after flash, which often results in blowing through the back wall of the vein.
  
• If you get flash but are not able to aspirate blood, it’s likely the needle is no longer in the vessel, either up against a back wall or through the back wall. The most common reason is that after flash, you unconsciously continue to move the needle forward, so simply withdrawing it slightly will often put you back into the lumen of the vein. If it does not draw back blood, do not attempt to pass a wire. In some hypovolemic patients, veins may collapse under suction and make drawing back difficult, but you will still be able to intermittently draw back.

The wire should pass freely and without resistance. Do not force past an obstruction. You can gently adjust the angle of your needle in case the wire is pushing up against a vessel wall, but more often, you’ll need to withdraw and reattempt. Repeated attempts at the same site increase the risk of bleeding complications and should prompt a change in strategy.

Before dilating the vessel, you must confirm venous placement. Dilation is a critical step. This is because while needle puncture of an artery is easily addressed with holding pressure, dilating an artery is a serious event that often requires vascular surgical repair. Arterial dilation can also result in stroke, dissection, and hemorrhage. To reduce the risk of inadvertently dilating or cannulating an artery, it is strongly recommended to use more than one method to confirm you’re in the vein. One method can be tracing the wire’s path via ultrasound, although this is not foolproof. A more reliable technique is to thread an IV catheter over the wire and attach a column of IV tubing to it. Venous blood will stay at a neutral height or drop (venous pressure is very low), while arterial blood will rise vigorously and in a pulsatile fashion.

Once you’ve confirmed proper placement, proceed with dilation and catheter insertion. Wire removal should be confirmed by an assisting provider.

Most central line complications fall into two major categories. First: trauma to adjacent structures, such as pneumothorax, hematoma, or carotid injury from the finder needle. These are usually preventable by maintaining continuous awareness of your needle tip and avoiding blind, aggressive probing. The second category is more serious: inadvertent cannulation of a nonvenous structure: artery, pleura, peritoneum, or soft tissue. This usually results from skipping key confirmation steps in an emergency or in a patient with difficult vascular access for whom multiple attempts were required.

If this happens, do not remove the line. As tempting as it may be, removal can precipitate uncontrolled bleeding or other serious complications. Intra-arterial lines require removal by a vascular surgeon who can safely control bleeding. Intrapleural lines may require chest tube placement or thoracotomy to avoid a tension pneumothorax on removal.

One final principle, which applies not only to central line placement but to all procedures in anesthesia: don’t fixate on a single technique. Do not keep poking a patient just because you are too proud to give up. With each attempt, the risk of complications rises sharply. Ask yourself: Should I change providers? Try a different site? Proceed without the line altogether? If the central line was placed for a mild indication, it may no longer be worth the risk. This mindset of reassessment, balancing necessity against risk, should guide every procedure you perform.